rtu_linux_modules/swapi/subjects/serial/serial.c

#include "swapi.h"
#include "swmem.h"
#include "swthrd.h"
#include "swtcp.h"
#include "swstring.h"
#include "serial.h"

struct serial_t
{
    /* fd */
    int fd;
    /* 名称 */
    char name[128];
    /* 波特率 */
    int baudrate;
    /* 校检位: "odd"-奇校检; "even"-偶校检; "no"-无校检 */
    char parityCheck[5];

    /* 原有配置 */
    struct termios oldtio;
    bool bGetOldtioOK;

    /* 数据接收线程句柄 */
    void *hRecvThrd;
    /* 数据接收缓存 */
    unsigned char recvBuf[65535];
    /* 已接收的字节数 */
    int nRecvBytes;
    /* 处理已接收的数据(用户回调) */
    PSerialRecvHandler pRecvHandler;
    /* 无数据空闲时执行(用户回调) */
    PSerialIdleHandler pIdleHandler;

    /* 日志打印前缀 */
    char log_prefix[MAX_LINE_CHARS];
    /* 日志打印缓存 */
    char *pLogRecvBuf; // 堆内存
};

/* 数据接收处理(线程回调) */
static int serial_data_recv_proc(unsigned long wParam, unsigned long lParam);

/* 打开串口(8个数据位1个停止位), NULL失败, NOT NULL成功 */
void *serial_open(const char *serialName, int baudrate, const char *parityCheck /* "odd"-奇校检; "even"-偶校检; NULL或其它无效值-无校检 */,
                  PSerialRecvHandler pRecvHandler, PSerialIdleHandler pIdleHandler, void *pUserData)
{
    struct serial_t *pSerial;
    struct termios newtio;
    int nSpeed;

    /* 1, 创建串口对象 */
    if(!serialName) return NULL;
    pSerial = (struct serial_t *)sw_heap_malloc(sizeof(struct serial_t));
    if(!pSerial) return NULL;
    else
    {
        memset(pSerial, 0, sizeof(struct serial_t));
        strncpy(pSerial->name, serialName, sizeof(pSerial->name)-1);
    }

    /* 2, 打开串口 */
    pSerial->fd = open(pSerial->name, O_RDWR | O_NOCTTY | O_NDELAY | O_CLOEXEC);
    if(pSerial->fd == -1) goto ErrorP;

    if(flock(pSerial->fd, LOCK_EX | LOCK_NB) == -1) goto ErrorP;

    /* 3, 保存当前串口配置 */
    if(tcgetattr(pSerial->fd, &pSerial->oldtio) == -1) goto ErrorP;
    else pSerial->bGetOldtioOK = true;

    /* 4, 设置阻塞 */
    if(fcntl(pSerial->fd, F_SETFL, 0) == -1) goto ErrorP;

    /* 5, 设置参数(8 databits, no parity, 1 stopbit, 1 second read timeout) */
    pSerial->baudrate = baudrate;
    switch(pSerial->baudrate)
    {
        case      0 : nSpeed = B0;       break;
        case     50 : nSpeed = B50;      break;
        case     75 : nSpeed = B75;      break;
        case    110 : nSpeed = B110;     break;
        case    134 : nSpeed = B134;     break;
        case    150 : nSpeed = B150;     break;
        case    200 : nSpeed = B200;     break;
        case    300 : nSpeed = B300;     break;
        case    600 : nSpeed = B600;     break;
        case   1200 : nSpeed = B1200;    break;
        case   1800 : nSpeed = B1800;    break;
        case   2400 : nSpeed = B2400;    break;
        case   4800 : nSpeed = B4800;    break;
        case   9600 : nSpeed = B9600;    break;
        case  19200 : nSpeed = B19200;   break;
        case  38400 : nSpeed = B38400;   break;
        case  57600 : nSpeed = B57600;   break;
        case 115200 : nSpeed = B115200;  break;
        case 230400 : nSpeed = B230400;  break;
        default     : goto ErrorP;
    }
    memset(&newtio, 0, sizeof(newtio));
    newtio.c_cflag = nSpeed | CS8 | CLOCAL | CREAD; // 设置波特率、数据带宽、本地连接、接收使能
    newtio.c_cflag &= ~CSTOPB; // 一个停止位
    if(xstrcasecmp(parityCheck, "odd") == 0)
    {  // 使能奇校检
        newtio.c_cflag |= PARENB; newtio.c_cflag |= PARODD;
        newtio.c_iflag |= INPCK; strcpy(pSerial->parityCheck, "odd");
    }
    else if(xstrcasecmp(parityCheck, "even") == 0)
    { // 使能偶校检
        newtio.c_cflag |= PARENB; newtio.c_cflag &= ~PARODD;
        newtio.c_iflag |= INPCK; strcpy(pSerial->parityCheck, "even");
    }
    else
    { // 无校检
        newtio.c_cflag &= ~PARENB;
        newtio.c_iflag = IGNPAR; strcpy(pSerial->parityCheck, "no");
    }
    newtio.c_oflag = 0;
    newtio.c_lflag = 0;
    newtio.c_cc[VMIN] = 0;  // read block untill n bytes are received, 阻塞模式有效
    newtio.c_cc[VTIME] = 1; // read block untill a timer expires(单位: 百毫秒, 十分之一秒), 阻塞模式有效
    if(tcflush(pSerial->fd, TCIOFLUSH) == -1) goto ErrorP; // 清空串口输入、输出缓存
    if(tcsetattr(pSerial->fd, TCSANOW, &newtio) == -1) goto ErrorP; // 激活新配置

    /* 6, 生成日志打印前缀 */
    if(xstrcasecmp(pSerial->parityCheck, "odd") == 0) sprintf(pSerial->log_prefix, "[%s:%d(odd parity)]", pSerial->name, pSerial->baudrate);
    else if(xstrcasecmp(pSerial->parityCheck, "even") == 0) sprintf(pSerial->log_prefix, "[%s:%d(even parity)]", pSerial->name, pSerial->baudrate);
    else sprintf(pSerial->log_prefix, "[%s:%d(no parity)]", pSerial->name, pSerial->baudrate);

    /* 7, 申请日志打印缓存 */
    pSerial->pLogRecvBuf = (char *)sw_heap_malloc(sizeof(pSerial->log_prefix)+MAX_LINE_CHARS+sizeof(pSerial->recvBuf)*2);
    if(!pSerial->pLogRecvBuf) goto ErrorP;

    /* 8, 打开串口数据接收线程 */
    pSerial->pRecvHandler = pRecvHandler; pSerial->pIdleHandler = pIdleHandler; // 用户回调
    pSerial->hRecvThrd = sw_thrd_create(pSerial->name, THREAD_DEFAULT_PRIORITY, 4*1024*1024, serial_data_recv_proc, (unsigned long)pSerial, (unsigned long)pUserData);
    if(!pSerial->hRecvThrd) goto ErrorP;
    else sw_thrd_resume(pSerial->hRecvThrd); // 激活数据接收线程

    return (void *)pSerial;

    /* 9, 错误 */
ErrorP:
    serial_close(pSerial, 0);
    return NULL;
}

/* 关闭串口 */
void serial_close(void *hSerial, int timeout)
{
    struct serial_t *pSerial = (struct serial_t *)hSerial;

    if(pSerial && pSerial->hRecvThrd) sw_thrd_destroy(pSerial->hRecvThrd, timeout); // 销毁数据接收线程

    if(pSerial->pLogRecvBuf) sw_heap_free((void *)pSerial->pLogRecvBuf); // 释放日志打印缓存

    if(pSerial && pSerial->fd != -1)
    {
        if(pSerial->bGetOldtioOK) tcsetattr(pSerial->fd, TCSANOW, &pSerial->oldtio); // 恢复原有的串口配置
        close(pSerial->fd); // 关闭串口
    }

    if(pSerial) sw_heap_free((void *)pSerial); // 释放内存, 销毁串口对象
}

/* 获取日志打印前缀 */
char *serial_get_log_prefix(const void *hSerial)
{
    struct serial_t *pSerial = (struct serial_t *)hSerial;
    if(pSerial) return pSerial->log_prefix;
    else return NULL;
}

/* 发送数据, -1失败, >=0发送的字节数 */
int serial_send_data(const void *hSerial, const unsigned char *data, int len)
{
    struct serial_t *pSerial = (struct serial_t *)hSerial;
    if(pSerial && pSerial->fd != -1)
    {
        int ret = write(pSerial->fd, data, len);
        if(ret < 0) sw_log_error("write error(ret=%d, errno=%d, %s), \"%s\" serial port send failed!!", 
                                 ret, errno, strerror(errno), pSerial->name);
        return ret;
    }
    else return -1;
}

/* 取得接收缓存区, NULL失败, NOT NULL成功 */
const unsigned char *serial_get_recv_buffer(const void *hSerial)
{
    struct serial_t *pSerial = (struct serial_t *)hSerial;
    if(pSerial) return pSerial->recvBuf;
    else return NULL;
}

/* 取得接收缓存区中当前有效数据的字节数, -1失败, 返回值>=0 */
int serial_get_recv_buffer_bytes(const void *hSerial)
{
    struct serial_t *pSerial = (struct serial_t *)hSerial;
    if(pSerial) return pSerial->nRecvBytes;
    else return -1;
}

/* 清空接收缓存区 */
void serial_clear_recv_buffer(const void *hSerial)
{
    struct serial_t *pSerial = (struct serial_t *)hSerial;
    if(pSerial)
    {
        memset(pSerial->recvBuf, 0, sizeof(pSerial->recvBuf));
        pSerial->nRecvBytes = 0;
    }
}

/* 打印接收缓存区 */
void serial_printf_recv_buffer(const void *hSerial, int logLevel)
{
    struct serial_t *pSerial = (struct serial_t *)hSerial;
    if(pSerial)
    {
        pSerial->pLogRecvBuf[0] = '\0'; // 复位日志缓存
        sprintf(pSerial->pLogRecvBuf, "%s the received buffer has %d bytes (hex)",
                pSerial->log_prefix, pSerial->nRecvBytes);
        if(pSerial->nRecvBytes > 0) { strcat(pSerial->pLogRecvBuf, ":\n");
        xstrfromhex(pSerial->recvBuf, pSerial->nRecvBytes, pSerial->pLogRecvBuf, NULL, NULL); }
        else strcat(pSerial->pLogRecvBuf, ".");
        sw_log_writeWithLevel(logLevel, __FILE__, -1, "%s", pSerial->pLogRecvBuf);
    }
}

/* 判断接收线程是否还在 */
bool serial_recvThrd_isAlive(const void *hSerial)
{
    struct serial_t *pSerial = (struct serial_t *)hSerial;
    return pSerial ? sw_thrd_isAlive(pSerial->hRecvThrd) : false;
}

/* 暂停接收线程接收数据 */
void serial_recvThrd_pause(const void *hSerial)
{
    struct serial_t *pSerial = (struct serial_t *)hSerial;
    if(pSerial) sw_thrd_pause(pSerial->hRecvThrd);
}

/* 继续接收线程接收数据 */
void serial_recvThrd_resume(const void *hSerial)
{
    struct serial_t *pSerial = (struct serial_t *)hSerial;
    if(pSerial) sw_thrd_resume(pSerial->hRecvThrd);
}

#ifdef _DEBUG
/* 向接收缓存中写入数据(一般用于仿真串口输入, 模拟测试时使用) */
void serial_write_recv_buffer(const void *hSerial, const unsigned char *hex, int hexCnt)
{
    struct serial_t *pSerial = (struct serial_t *)hSerial;
    if(pSerial && hex && hexCnt > 0 && hexCnt < sizeof(pSerial->recvBuf))
    {
        memcpy(pSerial->recvBuf+pSerial->nRecvBytes, hex, hexCnt);
        pSerial->nRecvBytes += hexCnt;
    }
    sw_thrd_delay(1000); // 延时1秒钟, 等待数据被回调处理, 否则会累积(模拟仿真和真实触发还是有区别)
}
#endif

/* 检测串口状态, timeout单位为ms */
#define serial_select sw_tcp_select

/* 数据接收处理(线程回调), "返回值 < 0"时表示处理失败, 将不再调用该接收回调函数, "返回值 >= 0"时表示
   处理成功, 延时一段"返回值"时间(ms)后继续调用该接收回调函数 */
static int serial_data_recv_proc(unsigned long wParam, unsigned long lParam)
{
    struct serial_t *pSerial = (struct serial_t *)wParam;
    fd_set rSet;
    int nRecvBufSize = sizeof(pSerial->recvBuf), nInterval, nRet;

RecvP:
    if(!sw_thrd_isAlive(pSerial->hRecvThrd)) return -1;

    nRet = serial_select(pSerial->fd, &rSet, NULL, NULL, 0);
    if(nRet == 0)
    { // 串口无数据
NoneP:
        if(pSerial->pIdleHandler) nInterval = pSerial->pIdleHandler(wParam, lParam); // 触发无数据时的用户回调
        else nInterval = 1;
        goto EndP;
    }
    else if(nRet > 0 && FD_ISSET(pSerial->fd, &rSet))
    { // 串口有数据
        if(pSerial->nRecvBytes >= nRecvBufSize)
        { // 判断接收缓存是否溢出
            sw_log_warn("\"%s\" serial port receiving buffer overflow, the earliest one byte(%02x) will discard!",
                        pSerial->name, pSerial->recvBuf[0]);
            memmove(pSerial->recvBuf, pSerial->recvBuf+1, nRecvBufSize-1); // 丢弃最早的一个字节
            pSerial->nRecvBytes = nRecvBufSize-1; // 新的已接收字节数
        }

        nRet = read(pSerial->fd, pSerial->recvBuf+pSerial->nRecvBytes, 1); // 读一个字节
        if(nRet == 1) pSerial->nRecvBytes += 1; // 已接收字节数累加1
        else if(nRet == 0 && errno == ETIMEDOUT) goto NoneP; // 读数据超时
        else
        { // 读一个字节错误
            sw_log_error("read one byte error(ret=%d, errno=%d), \"%s\" serial port receiving thread abort!!",
                         nRet, errno, pSerial->name);
            return -1;
        }

        if(pSerial->pRecvHandler)
        { // 处理已接收的数据
            nInterval = pSerial->pRecvHandler(wParam, lParam); // 触发有数据时的用户回调
            if(nInterval < 0) goto EndP;
        }

        goto RecvP; // 继续接收后续数据
    }
    else if(nRet < 0 && errno != EINTR)
    { // 有错误发生
        sw_log_error("select error(%s), \"%s\" serial port receiving thread abort!!", strerror(errno), pSerial->name);
        return -1;
    }
    else nInterval = 1; // 不满足上述组合判断条件时

EndP:
    return nInterval;
}